The ATP2B4 Knockout SK-HEP-1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal cell population featuring targeted disruption of the human ATP2B4 gene, which encodes plasma membrane calcium ATPase 4 (PMCA4). This product provides a stable loss-of-function model within the SK-HEP-1 host cell line, enabling researchers to interrogate the roles of PMCA4-mediated calcium extrusion and its downstream signaling cascades. The polyclonal knockout format ensures a heterogeneous cell pool with diverse editing outcomes across the population, avoiding clonal selection artifacts while maintaining robust gene-level ablation suitable for functional genomics studies.
The host cell line, SK-HEP-1, is a well-characterized human hepatic adenocarcinoma cell line originally derived from the ascitic fluid of a patient with liver adenocarcinoma. Widely employed in hepatocellular carcinoma (HCC) research, SK-HEP-1 cells exhibit malignant properties including anchorage-independent growth and tumorigenicity, making them a relevant model for investigating liver cancer biology. Their human origin provides a clinically pertinent context for studying calcium-dependent signaling alterations in hepatic malignancy.
ATP2B4 encodes PMCA4, a high-affinity plasma membrane Ca2?-ATPase that extrudes cytosolic calcium, thereby terminating Ca2? signals and replenishing extracellular calcium stores. PMCA4 activity is regulated by calmodulin, PKA, PKC, and transcriptional factors such as SP1 and NFAT. Mechanistically, PMCA4 functionally interacts with scaffolding proteins including NHERF1, NOS1, ??-1 syntrophin, and caveolin-1, forming localized signaling complexes. In SK-HEP-1 cells, CRISPR/Cas9-mediated ATP2B4 disruption eliminates PMCA4-mediated calcium efflux, leading to sustained elevations in intracellular Ca2?. This hyperactivates calcineurin/NFAT signaling, promoting NFAT nuclear translocation and transcriptional induction of targets like Cyclin D1. Concomitantly, uncoupling of PMCA4 from NOS1 impairs eNOS activity and nitric oxide/cGMP signaling, while altered interactions with Dishevelled modulate Wnt/??-catenin pathway output.
Within the hepatocellular carcinoma context, loss of PMCA4 profoundly dysregulates calcium homeostasis, fueling oncogenic pathways that drive proliferation, survival, and migration. Elevated cytosolic Ca2? enhances calcineurin-mediated NFAT dephosphorylation, a critical event in HCC cell cycle progression and resistance to apoptosis. Disrupted PMCA4-NOS1 complexes reduce nitric oxide bioavailability, further compromising growth-inhibitory cGMP signals, while aberrant Wnt/??-catenin activity reinforces transcriptional programs underlying malignant phenotypes. This knockout model thus enables precise dissection of PMCA4-dependent mechanisms in liver cancer pathogenesis and serves as a platform for evaluating pharmacological interventions targeting these pathways.
The ATP2B4 Knockout SK-HEP-1 Polyclonal Cells are ideally suited for a broad spectrum of functional assays, including intracellular calcium imaging with Fluo-4 AM, NFAT luciferase reporter assays to monitor calcineurin activity, and phospho-ERK Western blotting. Proliferation and migration can be assessed via MTT and Transwell assays, while apoptosis is evaluated using Annexin V staining. Additionally, this model supports drug sensitivity testing and validation of anti-cancer agents, as well as genetic analysis such as Sanger sequencing and RT-qPCR. Researchers may also employ it to investigate ATP2B4 variants associated with reduced malaria susceptibility, exploring host-pathogen interactions in hepatocytes. For further inquiries, please contact Ascent Research.
